Pain that occurs when you bite down is one of the most specific and localized symptoms in dentistry. This sensation often presents as a sharp jolt or a dull ache upon the application of pressure. Unlike generalized tooth sensitivity to temperature, this “biting pain” almost always points toward a mechanical problem or an infection aggravated by force. It is a clear signal that the structure of the tooth, the surrounding supporting tissues, or the internal nerve is physically reacting to the load of chewing. The nature of the pain—whether it is momentary or lingering—provides dentists with immediate clues about the underlying cause.
Pain Caused by Structural Integrity Compromise
One of the most frequent causes of pain when biting is a structural failure within the tooth itself, commonly diagnosed as Cracked Tooth Syndrome. This refers to an incomplete fracture of the tooth structure, often extending from the chewing surface downward. The pain occurs because the force of biting pushes the two fractured pieces apart, stimulating the sensitive inner dentin and pulp. When the pressure is released, the fragments snap back together, causing a sharp, brief pain.
Failed dental work, such as a loose filling or a cracked crown, can also lead to this distinct sensation. If an old restoration lifts or shifts under the pressure of chewing, it can expose the underlying dentin to the forces of the bite. This minor movement irritates the tooth’s structure. Similarly, a fractured cusp will cause pain as the broken piece moves during the chewing cycle. Even a new filling or crown that is slightly “high” can cause pain, as it absorbs excessive force before the other teeth meet, leading to inflammation of the ligament that holds the tooth in place.
Pain Stemming from Internal Nerve and Pulp Issues
When pain upon biting lingers instead of disappearing immediately, it often indicates a deeper issue involving the tooth’s internal nerve, known as the pulp. Deep decay that progresses into the pulp chamber can cause pulpitis, which is inflammation of the nerve tissue. The rigid structure of the tooth prevents the swollen tissue from expanding, creating internal pressure. This existing pressure is then aggravated by the external force of biting down.
If the infection spreads beyond the root tip and into the jawbone, a periapical abscess can form, creating a pocket of pus. This fluid-filled sac generates pressure within the bone surrounding the tooth’s root. When a person bites, the force is transmitted through the tooth to the inflamed ligament and the abscess pocket, resulting in a throbbing, intense pain. This pressure sensitivity is a hallmark of an abscess. In these cases, the nerve may even be dead (necrotic), but the force of the bite is still causing pain in the surrounding infected tissues.
Referred Pain from Surrounding Tissues
Not all biting pain originates from damage to the tooth itself; sometimes, the cause lies in the supporting structures or nearby facial anatomy. The periodontal ligament (PDL) anchors the tooth root to the jawbone. If the PDL becomes inflamed—for instance, from persistent teeth grinding (bruxism) or recent heavy dental work—the tooth will be tender to any touch or pressure. This condition, known as periodontitis, causes pain when biting because the force directly stresses the already irritated ligament fibers.
Referred pain from the sinuses is another common differential diagnosis, particularly for the upper back teeth. The roots of the maxillary molars and premolars lie in close proximity to the floor of the maxillary sinuses. When a person experiences a sinus infection or severe congestion, the resulting internal pressure can press on the nerve endings near the tooth roots. This can cause a dull, widespread ache that is noticeable when chewing or moving the head. Finally, Temporomandibular Joint (TMJ) disorders can cause muscle and joint pain that radiates to the teeth, making it feel like a tooth problem when the jaw movement of biting is the actual trigger.
Immediate Self-Care and Professional Examination
While waiting for a dental appointment, you can take several steps to manage the discomfort and prevent further injury. The most important action is to completely avoid chewing on the affected side of your mouth and switch to a soft-food diet. Over-the-counter anti-inflammatory medications, such as ibuprofen, can help reduce the swelling in the irritated pulp or periodontal ligament, offering temporary relief from the pressure-induced pain. Applying a cold compress to the outside of the cheek near the painful area can also help to numb the area and reduce any external swelling.
A professional diagnosis is mandatory for this specific symptom, as the cause is rarely superficial. The dentist will perform a series of focused tests to isolate the problem tooth. These diagnostic procedures include:
- A bite test, where you are asked to bite down on a specialized device to reproduce the pain, which helps pinpoint the exact location.
- Transillumination, using a bright fiber optic light, which can reveal hairline fractures that are otherwise invisible to the naked eye.
- X-rays, taken to check for signs of decay, bone loss, and the dark shadow of an abscess at the root tip.